1. Field of the Invention
This invention relates to computer memory systems and, more particularly, to data transfer between a memory controller and a memory unit.
2. Description of the Related Art
Computer systems employ many different types of system memory. One common type of system memory is implemented using removable memory modules. Memory modules come in different types and configurations. However in general, a memory module may be implemented as a printed circuit board having an edge connector and a number of memory devices. The memory module may be plugged into a socket located on a motherboard or other system board. A commonly used memory module is known as a dual in-line memory module (DIMM), although there are others. In other systems, memory devices may be non-removable and may be mounted directly to the motherboard or system board.
Computer system processor speed and performance have increased rapidly in recent history. However, system memory performance has typically lagged behind. As such, some system performance improvements may be limited by the performance of the system memory. Thus, improvements in system memory bandwidth and capacity may be of great concern to the system architect.
Although improvements in system memory performance are possible, these improvements are sometimes costly. As such, it may be desirable to improve system memory bandwidth and capacity while keeping costs down.